End brush construction



y 9, 1961 R. o. PETERSON 2,982,983

END BRUSH CONSTRUCTION Filed May 22, 1957 2 Sheets-Sheet 1 INVENTOR. RUBEN O. PE7ER50N ATTORNEYS.

y 1961 R. o. PETERSON 2,982,983

END BRUSH CONSTRUCTION Filed May 22, 1957 2 Sheets-Sheet 2 MHIIM INVENTOR. PUBYEN 0. PE TER 501V ATTORNEYS.

' flucriptioneproceedsp a 3T0; the: accomplishment? of.th'e. .fore'g'oing and related;

United States Patent' END BRUSH CONSTRUCTION Filed May 22, 1951, Ser. No. 660,908: 22 Claims. (21. 15-180) This invention relates as indicated to a novel end brush, and more particularly to an' improved end brush in which the brush material is especially securely'retained as well 'as being distributed in a manner for particularly efficient operation.

The usual end brush now commercially employed on a rather large scale comprises a cup shaped holder within which a bundle of brush bristle material is retained. extending therefrom generally parallel to the axis of such cup. One form which has been particularly commercially successful is illustrated and described" in Beny ak Patent 2,449,158. When considering the mode of operation of end brushes, it becomes apparent" that more consideratio'n; ought to be given to certain factors' than has been the case in the past. Thus, there: is ordinarily no advantage in providing'any quantity of brush materialiu the exact axial center ofthebrush inasmuch as the; brush is rotated'about such axis in use and the bristles in' such 'centr al region will accordingly travel at relatively: slow speeds and' the central portion of the brush will have' a pivotal orboring action rather than a true brushing action as 'de'sired. In certain respects, accordingly, the wellknown cup brush maybe a more eflicienttooli'than the conventional end brush.

When folded bristles are retained within thecupofan end brush, such folded portions are ratherbulkyand limit the density of brush material fill which may be inserted-within the cup shaped holder. As may readily be understood; however, it" is ordinarily important to provide" a relatively dense brush material fill in the ra- Ldiallyjohterportithi of the cup. This is especially true -when relatively flexible brush material is to be employed which tends-to flare radially outwardly under-theiinfiuence of centrifugal force in use whenithe-tool isiid'riven at h h pe i V. A Brush bristle material has also been" secured in: cup ishaped holders'by means of sold'enand a relativelydense filli may be obtained in this'manne'r Such soldier; of course, can only be employed with metallic brush-bristle I firiaterial and" involves certain manufacturing problems;

In'many prior end l'n uslles, it' has been found that when the brush is forcibly pressed against the-work; vthere "may develop relative rotation between the cup shaped.

holderandfthe'bundl'e of brush material retained therein, obviously much reducing the 'efli'ciency ofthe tool. and usually resulting-in-its'early break-down; 1

Tn' vi'ew of the foregoing it is an im rtant olioject of my" invention to provide a; novelend brush which is Linea- 1. pensive of manufacture and'in which thebrush'material against rotation relative'to is fiiml'y secured andfheld "th'e cup shap'ed holder. a v V I Another object'is to rovide such end. bru'slr 'in which thebmsh material 'is exceptionallydensely compacted}. I in the radiall'y oute'rportions thereof andjisjmuch less --dens'eiir thecentral portionther'eofij w Other objects of "the 'nvention w' r appear laslthe he 2,982,983 P t e M .961

ice

. Z; ends, said'invention then comprises the features herein.- after fully described and particularly pointedout inv the claims, the. following description and the annexed drawing setting forth. in detail certain illustrative embodi- 5 ments of the invention, these beingindicative, however, of but a few of the various ways in which the principle 7 of the invention'may be employed:

In said. annexed drawing: Fig. 1 is a longitudinal section through a novel end brush embodying certain features of my invention;

Fig. 2 is alongitudinal section taken on' the line. 2.2 on Fig-1; I

Fig. 3 is a. bristle end. view lot the brush 'ofFigs. v 1 and 2; r

Fig. 4' is a longitudinal section through another end brush embodying certainaspects of 'my invention;

Fig. 5 is a longitudinal section taken on the. line 5-5 on Fig. 4;

Fig. 6 is a bristle end 'view' of the brush of Figs. 4an'd 5; 1

Fig. 7 is' a longitudinal section'through another modification embodying; certain principles of my invention, and more; particularly including a central plug or spreader; I 1 I Fig. 8: is al longitudinal section. taken v.on the. line 1 8-8' on Fig. 7; V

'Fig. 9 abristle 7' and 8; Fig. 10 isa longitudinal section through another form' of endibrush 'in' accordance with my inventionutilizing a. somewhat different type of' center -plug and key element; Fig ll is'an end view'of the cup shaped'holder of Fig.- 10', prior to insertionofthe brush material;

Fig. 12. is a longitudinalsection'through an end brush of theFi'g. 1 typehaving, however, a central plug and pilot member mounted thereon; T.

Fig 13 is: a longitudinal section taken on the line 13 -13onFig.l2;and 'b Referring now more particularly to the drawing and especially Figs; l-3 -thereof; theend' brush there'illustrated 'comprisesthe usual cupishaped' holder having a cup'p'orl 'tioril and an axially" extending shank'or 'steni Z protrud ing f'ronrthebase-'thereofi fWhile such cupshaped holder '-may be ofvarious'imaterials itwill ordinarilybe dental such assteel. A-"transversely extending key member-i3 v. I

is forcibly-inserted within'the cup 1' such key being-in #the form of a hard metal blade" (preferably; of: harder 5o 'materialfthan the cup) and slightlybversize sothat 'the' 1 foini edges thereofengaging the'arcuate inner peri-ph'ery of the cup bite; into. the"1att'er a manner firmly-1e secure" such keyf in' placei 'It willbe understooddhat 'suclf key] will" ordinarily be of rectangular longitudinal cross section as shown so as to proviide such fourcorrier edges adapted to-bite-into jthe material Qf thetf she "11 lholder. Othen'modification's anyhewevargc v u'sly feasible. The key or blade 3lwillusually be force a the cup umilgits inner side" is spaced only a "short tance from; the bottom ofi the cup but the smear 'ent' of the blade depthwis'e of" the cup is' "ordinarily-not end? w of the brush mag.

'-;.gbrushi bristlesjis sIorced;intorthei cupashapeddholfi traw mm,

bundle of bristles into the holder with consequent division of the bundle into two substantially equal tufts also results in further compacting of the inner ends of the bristles to provide tufts of increased density at their inner ends. Such inner ends of the bristles also displace and force upwardly the adhesive in the cup and thereby become coated with the adhesive bonding agent (preferk ably an epoxy resin composition)" The lip 6 of cup 1 will now desirably be flanged inwardly slightly and the brush may be placed in an oven to set the bonding. agent to form a relatively rigid block 7 which serves to bond the bristle end portions together, fixed their relative relationship one to another, and to bondthem to the. cup shaped holder 1 as well as to the'transversely' extending key 3. Such key, of course, locks this inner block of .material against rotation'relativeto the cup shaped holder 1.

' The inturned lipi6 of'the' holder cup 1 further assists in securing the inner block 7 against axial withdrawal and serves, moreover, as additional assurance that the key 3 will not shift axially of the cup.

Inasmuch as key Sextends diametrically of cup'l, it will be apparent that it displaces brush material not only centrally of the brush face (where such brush material is .not desired), but also in the regions adjacent the radially 'outer periphery of the brush face. Percentagewise, however, the reduction in over-all brush bristle density. in

4 permitted to touch elsewhere. It will accordingly be seen that a brush is produced quite similar to that of Fig. l but with an even greater proportion of the bristle material compacted in the outer peripheral portions of the brush.

In Figs. 10 and 11, a rather diiferent form of end brush construction is shown in which the key element does not extend from side to side of cup 1 diametrically thereof, .but is too short to contact the inner periphery of the cup. This key member is in the form of a bullet-shaped central plug or spreader element 13 having diametrically opposite thinlateral extensions or wings 14 and'15. The

inner end of bullet portion 13 is provided with a co-axial such outer peripheralregion is very small and is substan- J tially compensated for by the compacting. action of the .knife-edged' key at the time the bundle of brush material is inserted in the holder. In other words, the average density of the brush face is high in its outer peripheral region and substantially reduced in its central region below what it would be without such key. Furthermore, by action of centrifugal force when the brush is rotated in use, the central space is enlarged relative to its size when the brush is not rotating and the brush material tuft will spread outwardly along a definitely fixed line. Also, the parting of the brush material tuft into two divisions gives chip room which is advantageous in the case of certain types of brushing jobs for which these brushes are especially suitable.

Now referring to Figs. 4-6 inclusive of the drawing, the embodiment of my invention there illustrated is basically similar to that above described, and the various components are assembled. in the same general manner. The transversely extending blade or key '8 is, however, relatively thick sothat the brush bristle material is effectively divided into two separate tufts 9 and 10 which have a greatly reduced tendency to merge or touch t at the work face of the brushwhenrotated in use. The outer end faces such as 11 of key 8 are slightlybevelled to accommodate the inturned lip 6 of cup 1. As shown,

not only is the key or blade 8 considerably wider than key 3 relative to the cup diameter but also such keyelemerit protrudes outwardly beyond the cup, and it is this factorwhich is effective in accomplishing a pronounced 1dividing of the bundle of brush material into the two -generally semi-circular tufts 9 and 10. The, outer portion of key 8 begins to taper to an .edge just before the -point where. it begins to project beyond the lip 6 of.the

Now referring to, Figs.'79 inclusive .ofthe drawing,

. the embodimeint of my inventionthere illustrated in ef- ,fect combines'certain features of the two formsof end brush described above. The inner blade or key 3 has ;pr ess-fitted'or otherwise attachedjthereon midway. of its .glength a bullet-shaped plug '12, the cylindrical portion of .wh s naxb of a dia e pp x y q l o onethirdthej inner diameter of cup 1, or some other substanftialramquntl j Such bullet-shaped plug1 12 accordingly i. positioned co'axially of cup 1: and'spindle 2 and. when 'l the ib'undlel: of brush bristle. material :-'is now. inserted the. cup, it is not} only .divided into two but 5 "such tufts are spread a art inthecemral region although l mmas pilot for 'guidin'g the operation of the tool.

extension 16 press-fitted or otherwise secured within a corresponding co-axial recess in the bottom of cup 1. Two prongs 17 and 18 at or near the radially outer edges of wing portions 14 and 15 are driven into the bottom of cup 1 simultaneously with the insertion of extension 16 into its recess, thereby to ensure that this central spacer means is secured against rotation relative to cup 1. It will be apparent that this form of end brush is generally similar to that of Figs. 7-9 inclusive insofar as the distributionof the brush bristle material is concerned except that, of course, such brush bristle material extends in an uninterrupted circle from the holder. The bundle of brush' bristles forced into the holder is spread and compacted by the bullet-shaped central portion 13 and by, the wing members 14, the outer arcuate edges of which are sharp .for this purpose. The axial length of this central spreader element will ordinarily be approximately the same as the depth of cup 1 but may be varied to achieve different degrees of flare of the brush bristle material where the latter protrudes from the cup. As in the case of the previously described examples, the resin bonding agent will be employed in the same manner. Of course, whenusing wire bristle material, solder may be employed as the bonding agent although ordinarily the epoxy resin compositions will be much preferred. Among -these preferred compositions are epoxy resin plasticized with polyethylene glycol and epoxy resin plasticized with liquid Thiokol polymer. Other adhesives and bonding agents may be utilized, but ordinarily are less tenaciously adhesive than such preferred materials. The brush material bundle tends to fill the whole cavity of a brush 'back and the preferred adhesive placed therein is displaced upwardly on'insertion of the brush material bundle and thereby coats the brush material strand ends and on curing securely joins them together wherever they .'.contact one another and by this means the bundle end is greatly reduced in compressibility and greatlyincreased .in'rigidity even though it may still be somewhat porous in the butt region. In the form shown in Figs. 1214 inclusive, the knife edged key or blade3 is utilized much in the manner of 'theFig. 7 embodiment, but instead of the bullet-shaped .23 is inserted and securedin thesame general manner described above but such materialwill, of course, be of p "a length selected to causepilot portion 21 to project therebeyond. End brush pilots are generally well known in the and are adapted to enter openings inthe work :properly to, center the brush for the desired operation. The center plug or spacer element in this case accordingly ,serves several purposes, namely to spread and compress :the' brush bristlematerial when .-it is" inserted into the -;holder, to provide an especially dense brush face in the outer peripheral regions. thereof, to elirninatebrushmaterialfrom the central region bf thelbrush where such brush material is ineffective and undesirable, and to as my invention:

' bristle material and said holder;

4. 1.The rotary end brush of claim- 1', wherein sa member-L is ,spaced'fromthebottom of said -cup shaped 'holde t It'will now be seen that the objects of my invention have been achieved in a manner which perrr'iits' manufacture of my new end brush by methods suitable for mass production, thereby much reducing the cost of the finished article. j The 'brush material is secured in placefin an unusually jfirm' manner and -i s, moreover, rigidly, locked against rotation as'a'body relative to the'h'older'. 711'! the past, due to the fact that brush mater ial in the central region of the brush fac -ha's-- not been subjected to the same rate of wear as the 'briish material in :the outer peripheral regio'msuch Brushes-have tended lgradually to become centrally pointed contour and have often had to be discardedbefore' they wereotherwise worn out. In contrastther eto, my 'nevv end brushes' are dong-lived and maintain a high operating efliciency Zthro'ughout a greater portion of such life, Due to their construction, moreover, my end brushes "afford certain of the advantages ordinarily associated with cup brushes but provide considerably greater bristle density than has previously been available insuch latter type of brushi'f Any desired type of brush material may be utilized in my new end brush including various fibers such as tampico fiber, and composite bristle materials suchas nylon coated glass fibers and nylon coated wire, but

metal wire, especially slightlycrimped steel wire, is most' commonly employed. The keymember, such-as key 3, may desirably be a hard tool .steelblade capable of biting into the softer metal of the cup. Various types of collars and bridles are adapted to be used in conjunction with my brush to control the action of the ibr istle material and prolong the life thereof. Very hard materials such as glass and steel filaments having a Knoop hardness in excess of 600 may be employed inasmuch as they need not be folded to be retained in the holder in accordance with my invention. Such filament will, however, desirably be provided with thin tough vibration damping plastic coatings, such as nylon, to prolong their useful life, and the resin body 7 may desirably be somewhat resiliently deformable, although solid, to further avoid concentrations of stress in such cases.

The central plugs and pilot members mentioned may be brazed in place on the respective key elements and that of Fig. 10 may likewise be brazed to the bottom of the cup. I 7

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed. t

I therefore particularly'point out and distinctly claim 1. A rotary end brush comprising a cup shaped holder, a transversely extending key member within such cup having its ends in driven fit with"the in'terior wallfof such cup parallel to the axis oif such cup brush bristle, material-inserted in such: cup on each side of said key 5. The rotary; end brush zofirclaim ,1, wherein said member is spaced from the lip. of said, cup shaped hqlder v and said lip isfturned slightly to constrict" the month of the cup.

the side away from thebottom of such cup 7. The rotary end brush .of' claim l, wher ein Sanity member, is provided with an outwardly directed jedge ;QI1 thezside away'fronithe bottom of suchcup and said key rmer'nber' is also provided with edges extending generally 'parallel to the side Wall and .axis' of such cup adaptedjto bite into'such wall to lock" said key member againstth possibility of rotation rel'ativ'e' lto said holder. v

'8. The rotary end brush of claim 1, including a central axially disposed plug member of general cylindrical form mounted on said hey memberfand projecting -he-- yond the respective sides of the latter to displace brush material from the central portionxofthe brush face. q

member and extending from the cup in adirectiongencrally'parallel to the axis of the latter, and-bonding matcrial within such cup shaped holder effective to bond the Y.

"butt ends of said bristles together into a mass for rotation as a unit with said holder, said key. memb'er ensuring against relative 'rotationi oi the body of brush 2; The rotary end brush of claim 1;, wherein said bond irig material'kis' also effective to bond said bristles vto said (holder-andkey-member. a sl 3. The rotary end brush of claim 1, wherein said'bond 7 ing material is -an epoxy resin composition efie-ctive to coibond said bristles to said holder and key member, said I bondingmaterial likewise beingefiective to reduce the -compressibility*andincrease the figidity of-'the body of bristle butt end portions joined together thereby;

key

9. The rotary .ren'd brush of claim 1, including a cen --tral axially disposed plug member of generalcylindrical form mounted on said key member and projecting beyond the respective sides of the latter to displace brush material fromthe central portion of the brush face, said plug member also protruding axially outwardly beyond such brush face to serve as a pilot member.

10. The rotaryend brushwof claim '1, wherein said 'cup shaped holder is'of steel, said brush bristle material is steel wire, andsaid' bonding material is an epoxy resin composition eflective also '10 bond the body f bristles to the inner wall of said cup shaped holder and to said key member.

11. A rotary end brush comprising a cup shaped holder, a transversely extending key member secured within such cup having a knife edge directed outwardly toward the mouth of the cup, brush material inserted and compacted in such cup on each side of said key member and extending from the cup in a direction generally parallel to the axis of the latter, and bonding material within such cup shaped holder effective to bond the inner portions of such brush material together into a substantially rigid body for rotation as a unit with said holder and also effective to bond such brush material to said holder and key member, said key member ensuring against relative rotation of the body of brush material and said holder.

12.,The rotary end brush of claim 1l, wherein said I v v of said projecting portion of said key member being beveled and the lip of such cup'being slightly inturned to engage such beveled portion of said key member to i assist in retairiingthe same in place.

J15. The rotary'endfbruSh of cl'mf ll, including a central axially disposed plug member mounted on said key member and having anaxially outwardly pointed end "portion; v z y 16.; The rotary ends brush} of claimll', including a "central axially disposed plug memberniounted'on said j keyjmer'nber and, protruding axially Qoutwardly beyond i fthe brush face toserveas a pilot member, said plugf 'f member having a conical step thereon in the region where said brush material emerges from such cup.

;;'l7."Thez'rotary end brush of claim 11, wherein said Y key membercomprisesacentral bullet-shaped portion having an 'axialsternpress-fitted within a central recess, in the bottorin of-such cup, and laterally extending wing-- portionscf less thickness than said: central portion, saidwing portions having projections at their inner ends adapted to bite into the bottom of such cup to prevent rotation of said key member relative thereto, and said wing portions also being knife edged in their axially outer regions.

1 18. The method of manufacturing a rotary end brush which comprises driving a key member transversely into a cup shaped holder to cause the ends of. such key mem her to bite into the wall of suchholder, such key 'memher having an outwardly disposed edge, placing bonding material within such cup shaped holder, inserting a bun- -dle of brush bristle material axially into such holder with such bundle being divided by such edge of such key member and the divided portions of such bundle 'being further laterally compressed between such key member and the wall of such cup, and setting such bonding material to joint the inner butt end portions of such bristle material together and also to bond them to such cup and key member. i

19. A rotary end brush comprising'a bristle holder and two separate tufts of brush bristle material extendcircular brush face of much lower average bristle density in its central region than in its radially outer region.

.21. The method of manufacturing a rotary end brush which comprises driving a transversely extending key member into the inner bottom of a,cup shaped holder, placingbonding material within, such holder, inserting a bundle of brush material axially'into such holder, and seting such bonding material to jointhe inner butt end portions of such bristle material together and also to bond them to such cup and key member. v 22.. A rotary end brushcomprising a cup shaped holder, a retaining member entirely within such cup-shaped holder and extending transversely thereof entirely within such cup, and brushmaterial retained in said holder by said retaining member, the lip portion of said cup shaped holder being turned inwardly'to assist in securing said retaining member andassociated brush material therewithin.

References Cited in the file of this patent UNITED STATES PATENTS 935,326 Pushee Sept. 28, 1909 1,202,244 Timmis n. Oct. 24, 1916 1,889,494 Priest Nov. 29, 1932 2,449,158 Benyak Sept. 14, 1948 2,512,997 Bixler June 27, 1950 FOREIGN PATENTS 114,670 Switzerland Apr. 16, 1926 456,984

Germany Mar. 7, 1928 

